Q: Does your new 27" LED Cinema Display buzz?

Yes, I have exactly the same issues. Buzzing from the bottom right of the 27" Cinema Display when connected to my MacBook Pro (2008) and brightness is above 3/4.

Not mine

I have one of the previous generation 20" aluminium ACD and it buzzes when the brightness is set on anything lower than full... it actually becomes louder the lower the brightness is.

i've witnessed this on other ACDs i've used also - i assume it's a behaviour of the internal transformer, as less current is drawn. Transformer coil buzz is an age old problem.

I know what you mean about the volume of the noise, it's just above the level that makes it annoying. At first you think it's ok but after 10 minutes in quiet surroundings it drives you nuts.

Thankfully with mine i've always used it in a very bright environment and so setting it to max wasn't a problem.

but if yours does it on the highest setting then it's less easy to work around.

mine does the same thing. Very very annoying. I'd love to get a headcount on how many people have this problem. I bet it's 90% and the other 10% have bad ears. On most electronics power supply problems are pretty uniform. Mine kinda sounds like electronic interference (like when I get my iphone to close to desktop speakers...etc.) Thoughts?

Got mine last week, no buzz or sound issues so far.

yes, the reason it sounds like the electromagnetic interference that induces tones in speaker drivers (such as the microwave energy from cell phones) is because it is essentially the same mechanical action... which is a resonation electromagnetic coil (which will produce tones at whatever frequency it is vibrating).

The specific tones that it is producing are dependant on the electrical properties of the circuits attached to the coupled device - but it's probably possible that particular properties could cause the coils to create more than a single tone (just like a speaker)... on mine the tone didn't quite sound singular, but since the amplitude was analogue to the brightness i guessed that this pointed the transformer.

It used to be such a serious problem in inductively coupled conductive devices that it could shake the devices to pieces. These days it's only really an irritation in terms of noise - but it remains necessary to design the structure and housing of these devices to dampen and minimise these vibrations.

In much larger transformers the noise is very noticeable (have a listen the next time you pass an electrical substation).

... i could be wrong but it's a common problem in electronics and i think it's likely.

Thanks for the awesome explanation. Think it's a problem worth returning the monitor for? Will it get worse/better? Anyone else returned one for this or do all of the monitors do this? The sound is pretty feint. My 50 year old father couldn't hear it. Haha!

I'm not sure wether it would be worth the trouble... Apple may ether dismiss it as a problem or just give you another one which has exactly the same issue.

It might be worth trying to find the same model elsewhere to compare it too... i.e. find an apple store - or other store that displays ACDs at a quiet time of day. Then you can determine if it is a defect of that particular unit or a more widespread issue.

What a hard choice! It's a buzzing - not a "breathing" like the mac pro beside it. That's the only thing that bothers me. If I'm less than two feet away I can hear it, but then again I'm listening for it. I'm going to write up a report about it and send to apple. You think it'll get better or worse?

Any updates danny? What'd you end up doing...what'd apple say?

If it is the transformer buzz then it wont get better - it can only get worse (although i doubt very much it will).. if it's some other component then i don't know what way it could go.

But do send Apple a letter if you feel it is annoying enough... unfortunately i think this is probably a widespread issue not an isolated problem, and probably something that should be considered more carefully in the design of the device.

Hi guys,
I just found this exact same problem in my 24 inch model. I've had the thing for about eight months now and only just noticed it. I'm probably going to take it into the apple store after I've finished my semester exams, but do you think they would upgrade me to the 27 inch model if they found a fault since the 24 inch has now been dis-continued?

For my model they said it was not a defect and would not replace it.

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